make regexp View Helper work on tag content

not just the string argument
rework facets, their configuration, URL parameters and View Helpers
germania-sacra: update configuration (new facets, details)
introduce alternative faceting style by ANDing to the main query

this is quite problematic as it will not allow all combinations of queries (e.g. when facet queries begin wit {) and ugly for many
other reasons
germania-sacra: jahr50 & orden_standort_jahr50 für Facette